1. Field of the Invention
The present invention relates to an image processing apparatus capable of synthesizing image data with specific information of copy inhibition, copy guard and the like, which is different from the image data, and of performing processing corresponding to the read specific information.
2. Description of the Related Art
In image information inputted into an image processing apparatus, specific information, such as copy inhibition information and copy guard information, is embedded apart from image data in order to prevent illegal processing of a document. When detecting that the specific information is included in the inputted image information, the image processing apparatus performs predetermined processing corresponding to the specific information.
On the other hand, when reading a document in a state where dust or foreign matters are stuck to the document, the image processing apparatus may not be able to detect the embedded specific information. In order to prevent misdiscrimination of the specific information, the image processing apparatus is constituted so as to perform processing included in the specific information, when detecting a plurality of (five to six) pieces of the specific information in inputting image information, such as in reading the document.
In Japanese Patent Laid-Open No. 2001-94771, there is disclosed an image processing apparatus capable of inhibiting illegal copy of image data in such a manner that feature quantity data of the image data are compared with feature quantity data of a specific image, such as paper money or securities stored beforehand in a ROM, that a threshold value for a matching rate between the feature quantity data of the image data and the feature quantity data of the specific image is set for each kind of the image data, and that, when the matching rate is not smaller than the threshold value, image formation of the image data is not performed.
However, there are problems that when the number of pieces of the specific information is excessively increased, the influence of the specific information on the image becomes too large, and that when the number of pieces of specific information is too small, it is not possible to surely detect the specific information and to perform predetermined processing. These problems are caused because the specific information is incorporated at a predetermined interval regardless of the size of a document when the specific information is incorporated in the document. Therefore, in a small-sized document such as a postcard and a name card, the number of pieces of information detected as the specific information is reduced, which may result in a problem that the specific information cannot be surely recognized.
FIGS. 2(A) to 2(D) show examples of separable recording papers. FIG. 3 shows examples in which a number of pieces of specific information such as characters and symbols are arranged on a paper sheet 43. FIG. 3(A) shows an example in which a plurality of pieces of specific information 44 are sequentially arranged on an A4 size paper sheet, and FIG. 3(B) shows an example in which the plurality of pieces of specific information 44 are randomly arranged on the A4 size paper sheet. FIG. 3(C) shows a case where the paper sheet of FIG. 3(A) is divided into a plurality of label papers, and FIG. 3(D) shows a case where the paper sheet of FIG. 3(B) is divided into a plurality of label papers. When the A4 size paper sheet 43 is divided into a plurality of label papers 41, as shown in FIGS. 3(C) and 3(D), there is a case where the specific information 44a strides over a boundary 45 (section line) between the label papers 41 and thereby is interrupted in its midway.
In this case, the interrupted information 44a is not recognized as the specific information by a detecting section of the image processing apparatus, resulting in a problem that the number of detected pieces of the specific information is reduced so as not to exceed the threshold value, and the processing corresponding to the specific information such as copy inhibition cannot be correctly performed.
In view of the above, it is an object of the present invention to provide an image processing apparatus capable of synthesizing specific information such as copy inhibition with image data of a document without providing a sense of incongruity to the document, and of surely performing processing corresponding to the specific information.
A further object of the present invention is to provide an image processing apparatus capable of surely performing the processing corresponding to the specific information such as copy inhibition by making the threshold value variable according to the size of a document.